A key Democratic senator said this week she remains firmly opposed to changing federal election laws on a partisan basis, signaling that a planned last-ditch voting rights push that party leaders and activists are planning for the closely divided Senate in the coming months is likely to fail.

Sen. Kyrsten Sinema (Ariz.) is a co-sponsor of Democratic voting rights bills meant to combat state-level GOP efforts to restrict ballot access. But she has firmly resisted a campaign by some in her party to modify or eliminate the filibuster — the Senate rule requiring a 60-vote supermajority to advance most legislation — to pass them.

In an interview with The Washington Post on Thursday, about two weeks after Republicans blocked a third major voting rights bill, Sinema reiterated her stance.

“My opinion is that legislation that is crafted together, in a bipartisan way, is the legislation that’s most likely to pass and stand the test of time,” she said. “And I would certainly encourage my colleagues to use that effort to move forward.”

Asked about potential modifications to Senate rules — such as an exception to the filibuster for voting rights matters — Sinema cast doubt on whether such a maneuver would be workable.

“That caveat — ‘if it would even work’ — is the right question to ask,” she said.

The new statements come as Senate Majority Leader Charles E. Schumer (D-N.Y.) and other Democratic senators are strategizing with the White House, Vice President Harris and civil rights leaders over how to push voting rights legislation forward quickly after the Senate clears President Biden’s $2 trillion domestic policy agenda.

The 2022 gubernatorial races have taken on new significance for Democrats as Republicans push for more restrictive voting laws on the state level. (Mahlia Posey/The Washington Post)

Changing the Senate rules would require unanimity from the 50 Democratic senators, plus Harris’s tiebreaking vote, to overrule the chamber’s precedents. Schumer earlier this month said Democrats would “find an alternative path forward” to pass voting legislation “even if it means going at it alone.”

“Debate is central to this chamber’s character, but so is governing, so is taking action, when required, after debate has run its due course,” he said.

Biden acknowledged in October, during a televised town hall meeting, that he was reticent to push reluctant senators to upend Senate rules as long as his economic agenda hung in the balance. Schumer said Friday he hopes to clear that legislation as soon as next month.

“Here’s the deal: If, in fact, I get myself into at this moment the debate on the filibuster, I lose at least three votes right now to get what I have to get done on the economic side of the equation, on the foreign policy side of the equation,” Biden said.

But with the midterm elections less than a year away, Democrats are under mounting pressure from elected officials, activists and donors to act on national ballot-access standards and other voting provisions. A push to curb partisan congressional gerrymandering has already been overtaken, with more than 20 states having enacted new House district maps. But advocates say there is still time to set federal standards for early voting, vote-by-mail and voter registration, as well as to improve financial disclosure requirements for political groups.

Tiffany Muller, executive director of the advocacy group End Citizens United, said lawmakers have scant time to act. Not only are new redistricting maps going into effect, she said, but state legislatures will be coming back into session early next year to potentially pass new voting restrictions, and election administrators need time to implement any new federal mandates.

“We are not out of time yet,” she said. “But the time to act is now, and the attacks that our democracy are under are only increasing with each day.”

Muller said she was pleased that Sinema backs the policies that Democrats are hoping to pass, and “we’re going to continue to make the case to her . . . that we have to do whatever it takes to pass this critical legislation.”

Sinema is not the only Democratic senator who has openly questioned the need to change the filibuster. Sen. Joe Manchin III (W.Va.) has been similarly insistent about preserving the rules to promote bipartisan cooperation. But Manchin has, at times, signaled openness to some modifications, and he has worked with more-liberal colleagues to craft narrowed voting rights bills that could pick up some Republican support.

Those efforts have largely failed, with Senate Minority Leader Mitch McConnell (Ky.) and others in the GOP arguing that the federal government should have no further role in dictating state and local election laws.

No Republicans voted to advance Manchin’s compromise bill, the Freedom to Vote Act, in October, and only one Republican, Sen. Lisa Murkowski (Alaska), voted earlier this month to advance a bill that would restore provisions of the Voting Rights Act of 1965 that have been struck down by the Supreme Court.

Manchin declined to detail his views on next steps after the latter vote. “We need other people to be talking to each other and find the pathway forward,” he said. But he is under pressure from his colleagues — and from activists — to back rules changes to advance the legislation.

An ad running in Manchin’s home state, paid for by the West Virginia Freedom Alliance Action Fund, aims at nudging the maverick senator into action.

“Rules are important, but not as important as doing what’s right and saving democracy,” the ad says. “Time is running out. It’s up to Joe.”

Sinema detailed her reasoning in a June op-ed published in The Washington Post and in a July interview with ABC’s “The View.” “The filibuster compels moderation and helps protect the country from wild swings between opposing policy poles,” she wrote in June.

In the interview this week, Sinema suggested that those who expect her to revise those pronouncements have misjudged her.

“I don’t have a lot to say, typically, but when I do say something, I mean it,” she said. “That op-ed was something that was heartfelt, and it’s something that I believe very strongly.”

Seung Min Kim and Tony Romm contributed to this report.